diff --git a/arch/s390/kernel/machine_kexec.c b/arch/s390/kernel/machine_kexec.c
index fbde6a915264..60b1ea9f946b 100644
--- a/arch/s390/kernel/machine_kexec.c
+++ b/arch/s390/kernel/machine_kexec.c
@@ -63,6 +63,7 @@ NORET_TYPE void
 machine_kexec(struct kimage *image)
 {
 	clear_all_subchannels();
+	cio_reset_channel_paths();
 
 	/* Disable lowcore protection */
 	ctl_clear_bit(0,28);
diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
index a01f3bba4a7b..61ce3f1d5228 100644
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -1464,6 +1464,40 @@ chsc_get_chp_desc(struct subchannel *sch, int chp_no)
 	return desc;
 }
 
+static int reset_channel_path(struct channel_path *chp)
+{
+	int cc;
+
+	cc = rchp(chp->id);
+	switch (cc) {
+	case 0:
+		return 0;
+	case 2:
+		return -EBUSY;
+	default:
+		return -ENODEV;
+	}
+}
+
+static void reset_channel_paths_css(struct channel_subsystem *css)
+{
+	int i;
+
+	for (i = 0; i <= __MAX_CHPID; i++) {
+		if (css->chps[i])
+			reset_channel_path(css->chps[i]);
+	}
+}
+
+void cio_reset_channel_paths(void)
+{
+	int i;
+
+	for (i = 0; i <= __MAX_CSSID; i++) {
+		if (css[i] && css[i]->valid)
+			reset_channel_paths_css(css[i]);
+	}
+}
 
 static int __init
 chsc_alloc_sei_area(void)
diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index f27b2b866f5a..e36ca27f5777 100644
--- a/drivers/s390/cio/cio.c
+++ b/drivers/s390/cio/cio.c
@@ -876,5 +876,6 @@ void
 reipl(unsigned long devno)
 {
 	clear_all_subchannels();
+	cio_reset_channel_paths();
 	do_reipl(devno);
 }
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index a09deea5d687..13eeea3d547f 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -623,9 +623,13 @@ init_channel_subsystem (void)
 		ret = device_register(&css[i]->device);
 		if (ret)
 			goto out_free;
-		if (css_characteristics_avail && css_chsc_characteristics.secm)
-			device_create_file(&css[i]->device,
-					   &dev_attr_cm_enable);
+		if (css_characteristics_avail &&
+		    css_chsc_characteristics.secm) {
+			ret = device_create_file(&css[i]->device,
+						 &dev_attr_cm_enable);
+			if (ret)
+				goto out_device;
+		}
 	}
 	css_init_done = 1;
 
@@ -633,6 +637,8 @@ init_channel_subsystem (void)
 
 	for_each_subchannel(__init_channel_subsystem, NULL);
 	return 0;
+out_device:
+	device_unregister(&css[i]->device);
 out_free:
 	kfree(css[i]);
 out_unregister:
diff --git a/drivers/s390/cio/css.h b/drivers/s390/cio/css.h
index 15f7f7cb0ec2..8aabb4adeb5f 100644
--- a/drivers/s390/cio/css.h
+++ b/drivers/s390/cio/css.h
@@ -100,7 +100,7 @@ struct ccw_device_private {
 	struct qdio_irq *qdio_data;
 	struct irb irb;		/* device status */
 	struct senseid senseid;	/* SenseID info */
-	struct pgid pgid;	/* path group ID */
+	struct pgid pgid[8];	/* path group IDs per chpid*/
 	struct ccw1 iccws[2];	/* ccws for SNID/SID/SPGID commands */
 	struct work_struct kick_work;
 	wait_queue_head_t wait_q;
diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c
index cb1af0b6f033..ac6e0c7e43d9 100644
--- a/drivers/s390/cio/device_fsm.c
+++ b/drivers/s390/cio/device_fsm.c
@@ -378,6 +378,56 @@ ccw_device_done(struct ccw_device *cdev, int state)
 		put_device (&cdev->dev);
 }
 
+static inline int cmp_pgid(struct pgid *p1, struct pgid *p2)
+{
+	char *c1;
+	char *c2;
+
+	c1 = (char *)p1;
+	c2 = (char *)p2;
+
+	return memcmp(c1 + 1, c2 + 1, sizeof(struct pgid) - 1);
+}
+
+static void __ccw_device_get_common_pgid(struct ccw_device *cdev)
+{
+	int i;
+	int last;
+
+	last = 0;
+	for (i = 0; i < 8; i++) {
+		if (cdev->private->pgid[i].inf.ps.state1 == SNID_STATE1_RESET)
+			/* No PGID yet */
+			continue;
+		if (cdev->private->pgid[last].inf.ps.state1 ==
+		    SNID_STATE1_RESET) {
+			/* First non-zero PGID */
+			last = i;
+			continue;
+		}
+		if (cmp_pgid(&cdev->private->pgid[i],
+			     &cdev->private->pgid[last]) == 0)
+			/* Non-conflicting PGIDs */
+			continue;
+
+		/* PGID mismatch, can't pathgroup. */
+		CIO_MSG_EVENT(0, "SNID - pgid mismatch for device "
+			      "0.%x.%04x, can't pathgroup\n",
+			      cdev->private->ssid, cdev->private->devno);
+		cdev->private->options.pgroup = 0;
+		return;
+	}
+	if (cdev->private->pgid[last].inf.ps.state1 ==
+	    SNID_STATE1_RESET)
+		/* No previous pgid found */
+		memcpy(&cdev->private->pgid[0], &css[0]->global_pgid,
+		       sizeof(struct pgid));
+	else
+		/* Use existing pgid */
+		memcpy(&cdev->private->pgid[0], &cdev->private->pgid[last],
+		       sizeof(struct pgid));
+}
+
 /*
  * Function called from device_pgid.c after sense path ground has completed.
  */
@@ -388,24 +438,26 @@ ccw_device_sense_pgid_done(struct ccw_device *cdev, int err)
 
 	sch = to_subchannel(cdev->dev.parent);
 	switch (err) {
-	case 0:
-		/* Start Path Group verification. */
-		sch->vpm = 0;	/* Start with no path groups set. */
-		cdev->private->state = DEV_STATE_VERIFY;
-		ccw_device_verify_start(cdev);
+	case -EOPNOTSUPP: /* path grouping not supported, use nop instead. */
+		cdev->private->options.pgroup = 0;
+		break;
+	case 0: /* success */
+	case -EACCES: /* partial success, some paths not operational */
+		/* Check if all pgids are equal or 0. */
+		__ccw_device_get_common_pgid(cdev);
 		break;
 	case -ETIME:		/* Sense path group id stopped by timeout. */
 	case -EUSERS:		/* device is reserved for someone else. */
 		ccw_device_done(cdev, DEV_STATE_BOXED);
-		break;
-	case -EOPNOTSUPP: /* path grouping not supported, just set online. */
-		cdev->private->options.pgroup = 0;
-		ccw_device_done(cdev, DEV_STATE_ONLINE);
-		break;
+		return;
 	default:
 		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
-		break;
+		return;
 	}
+	/* Start Path Group verification. */
+	sch->vpm = 0;	/* Start with no path groups set. */
+	cdev->private->state = DEV_STATE_VERIFY;
+	ccw_device_verify_start(cdev);
 }
 
 /*
@@ -562,8 +614,9 @@ ccw_device_online(struct ccw_device *cdev)
 	}
 	/* Do we want to do path grouping? */
 	if (!cdev->private->options.pgroup) {
-		/* No, set state online immediately. */
-		ccw_device_done(cdev, DEV_STATE_ONLINE);
+		/* Start initial path verification. */
+		cdev->private->state = DEV_STATE_VERIFY;
+		ccw_device_verify_start(cdev);
 		return 0;
 	}
 	/* Do a SensePGID first. */
@@ -609,6 +662,7 @@ ccw_device_offline(struct ccw_device *cdev)
 	/* Are we doing path grouping? */
 	if (!cdev->private->options.pgroup) {
 		/* No, set state offline immediately. */
+		sch->vpm = 0;
 		ccw_device_done(cdev, DEV_STATE_OFFLINE);
 		return 0;
 	}
@@ -705,8 +759,6 @@ ccw_device_online_verify(struct ccw_device *cdev, enum dev_event dev_event)
 {
 	struct subchannel *sch;
 
-	if (!cdev->private->options.pgroup)
-		return;
 	if (cdev->private->state == DEV_STATE_W4SENSE) {
 		cdev->private->flags.doverify = 1;
 		return;
@@ -995,8 +1047,7 @@ static void
 ccw_device_wait4io_verify(struct ccw_device *cdev, enum dev_event dev_event)
 {
 	/* When the I/O has terminated, we have to start verification. */
-	if (cdev->private->options.pgroup)
-		cdev->private->flags.doverify = 1;
+	cdev->private->flags.doverify = 1;
 }
 
 static void
diff --git a/drivers/s390/cio/device_pgid.c b/drivers/s390/cio/device_pgid.c
index 54cb64ed0786..32610fd8868e 100644
--- a/drivers/s390/cio/device_pgid.c
+++ b/drivers/s390/cio/device_pgid.c
@@ -33,12 +33,17 @@ __ccw_device_sense_pgid_start(struct ccw_device *cdev)
 	struct subchannel *sch;
 	struct ccw1 *ccw;
 	int ret;
+	int i;
 
 	sch = to_subchannel(cdev->dev.parent);
+	/* Return if we already checked on all paths. */
+	if (cdev->private->imask == 0)
+		return (sch->lpm == 0) ? -ENODEV : -EACCES;
+	i = 8 - ffs(cdev->private->imask);
+
 	/* Setup sense path group id channel program. */
 	ccw = cdev->private->iccws;
 	ccw->cmd_code = CCW_CMD_SENSE_PGID;
-	ccw->cda = (__u32) __pa (&cdev->private->pgid);
 	ccw->count = sizeof (struct pgid);
 	ccw->flags = CCW_FLAG_SLI;
 
@@ -48,6 +53,7 @@ __ccw_device_sense_pgid_start(struct ccw_device *cdev)
 	ret = -ENODEV;
 	while (cdev->private->imask != 0) {
 		/* Try every path multiple times. */
+		ccw->cda = (__u32) __pa (&cdev->private->pgid[i]);
 		if (cdev->private->iretry > 0) {
 			cdev->private->iretry--;
 			ret = cio_start (sch, cdev->private->iccws, 
@@ -64,7 +70,9 @@ __ccw_device_sense_pgid_start(struct ccw_device *cdev)
 		}
 		cdev->private->imask >>= 1;
 		cdev->private->iretry = 5;
+		i++;
 	}
+
 	return ret;
 }
 
@@ -76,7 +84,7 @@ ccw_device_sense_pgid_start(struct ccw_device *cdev)
 	cdev->private->state = DEV_STATE_SENSE_PGID;
 	cdev->private->imask = 0x80;
 	cdev->private->iretry = 5;
-	memset (&cdev->private->pgid, 0, sizeof (struct pgid));
+	memset (&cdev->private->pgid, 0, sizeof (cdev->private->pgid));
 	ret = __ccw_device_sense_pgid_start(cdev);
 	if (ret && ret != -EBUSY)
 		ccw_device_sense_pgid_done(cdev, ret);
@@ -91,6 +99,7 @@ __ccw_device_check_sense_pgid(struct ccw_device *cdev)
 {
 	struct subchannel *sch;
 	struct irb *irb;
+	int i;
 
 	sch = to_subchannel(cdev->dev.parent);
 	irb = &cdev->private->irb;
@@ -124,7 +133,8 @@ __ccw_device_check_sense_pgid(struct ccw_device *cdev)
 			      sch->schid.sch_no, sch->orb.lpm);
 		return -EACCES;
 	}
-	if (cdev->private->pgid.inf.ps.state2 == SNID_STATE2_RESVD_ELSE) {
+	i = 8 - ffs(cdev->private->imask);
+	if (cdev->private->pgid[i].inf.ps.state2 == SNID_STATE2_RESVD_ELSE) {
 		CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x "
 			      "is reserved by someone else\n",
 			      cdev->private->devno, sch->schid.ssid,
@@ -162,12 +172,6 @@ ccw_device_sense_pgid_irq(struct ccw_device *cdev, enum dev_event dev_event)
 	memset(&cdev->private->irb, 0, sizeof(struct irb));
 	switch (ret) {
 	/* 0, -ETIME, -EOPNOTSUPP, -EAGAIN, -EACCES or -EUSERS */
-	case 0:			/* Sense Path Group ID successful. */
-		if (cdev->private->pgid.inf.ps.state1 == SNID_STATE1_RESET)
-			memcpy(&cdev->private->pgid, &css[0]->global_pgid,
-			       sizeof(struct pgid));
-		ccw_device_sense_pgid_done(cdev, 0);
-		break;
 	case -EOPNOTSUPP:	/* Sense Path Group ID not supported */
 		ccw_device_sense_pgid_done(cdev, -EOPNOTSUPP);
 		break;
@@ -176,13 +180,15 @@ ccw_device_sense_pgid_irq(struct ccw_device *cdev, enum dev_event dev_event)
 		break;
 	case -EACCES:		/* channel is not operational. */
 		sch->lpm &= ~cdev->private->imask;
+		/* Fall through. */
+	case 0:			/* Sense Path Group ID successful. */
 		cdev->private->imask >>= 1;
 		cdev->private->iretry = 5;
 		/* Fall through. */
 	case -EAGAIN:		/* Try again. */
 		ret = __ccw_device_sense_pgid_start(cdev);
 		if (ret != 0 && ret != -EBUSY)
-			ccw_device_sense_pgid_done(cdev, -ENODEV);
+			ccw_device_sense_pgid_done(cdev, ret);
 		break;
 	case -EUSERS:		/* device is reserved for someone else. */
 		ccw_device_sense_pgid_done(cdev, -EUSERS);
@@ -203,20 +209,20 @@ __ccw_device_do_pgid(struct ccw_device *cdev, __u8 func)
 	sch = to_subchannel(cdev->dev.parent);
 
 	/* Setup sense path group id channel program. */
-	cdev->private->pgid.inf.fc = func;
+	cdev->private->pgid[0].inf.fc = func;
 	ccw = cdev->private->iccws;
 	if (!cdev->private->flags.pgid_single) {
-		cdev->private->pgid.inf.fc |= SPID_FUNC_MULTI_PATH;
+		cdev->private->pgid[0].inf.fc |= SPID_FUNC_MULTI_PATH;
 		ccw->cmd_code = CCW_CMD_SUSPEND_RECONN;
 		ccw->cda = 0;
 		ccw->count = 0;
 		ccw->flags = CCW_FLAG_SLI | CCW_FLAG_CC;
 		ccw++;
 	} else
-		cdev->private->pgid.inf.fc |= SPID_FUNC_SINGLE_PATH;
+		cdev->private->pgid[0].inf.fc |= SPID_FUNC_SINGLE_PATH;
 
 	ccw->cmd_code = CCW_CMD_SET_PGID;
-	ccw->cda = (__u32) __pa (&cdev->private->pgid);
+	ccw->cda = (__u32) __pa (&cdev->private->pgid[0]);
 	ccw->count = sizeof (struct pgid);
 	ccw->flags = CCW_FLAG_SLI;
 
@@ -243,6 +249,48 @@ __ccw_device_do_pgid(struct ccw_device *cdev, __u8 func)
 	return ret;
 }
 
+/*
+ * Helper function to send a nop ccw down a path.
+ */
+static int __ccw_device_do_nop(struct ccw_device *cdev)
+{
+	struct subchannel *sch;
+	struct ccw1 *ccw;
+	int ret;
+
+	sch = to_subchannel(cdev->dev.parent);
+
+	/* Setup nop channel program. */
+	ccw = cdev->private->iccws;
+	ccw->cmd_code = CCW_CMD_NOOP;
+	ccw->cda = 0;
+	ccw->count = 0;
+	ccw->flags = CCW_FLAG_SLI;
+
+	/* Reset device status. */
+	memset(&cdev->private->irb, 0, sizeof(struct irb));
+
+	/* Try multiple times. */
+	ret = -ENODEV;
+	if (cdev->private->iretry > 0) {
+		cdev->private->iretry--;
+		ret = cio_start (sch, cdev->private->iccws,
+				 cdev->private->imask);
+		/* ret is 0, -EBUSY, -EACCES or -ENODEV */
+		if ((ret != -EACCES) && (ret != -ENODEV))
+			return ret;
+	}
+	/* nop command failed on this path. Switch it off. */
+	sch->lpm &= ~cdev->private->imask;
+	sch->vpm &= ~cdev->private->imask;
+	CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel "
+		      "0.%x.%04x, lpm %02X, became 'not operational'\n",
+		      cdev->private->devno, sch->schid.ssid,
+		      sch->schid.sch_no, cdev->private->imask);
+	return ret;
+}
+
+
 /*
  * Called from interrupt context to check if a valid answer
  * to Set Path Group ID was received.
@@ -282,6 +330,29 @@ __ccw_device_check_pgid(struct ccw_device *cdev)
 	return 0;
 }
 
+/*
+ * Called from interrupt context to check the path status after a nop has
+ * been send.
+ */
+static int __ccw_device_check_nop(struct ccw_device *cdev)
+{
+	struct subchannel *sch;
+	struct irb *irb;
+
+	sch = to_subchannel(cdev->dev.parent);
+	irb = &cdev->private->irb;
+	if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC))
+		return -ETIME;
+	if (irb->scsw.cc == 3) {
+		CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel 0.%x.%04x,"
+			      " lpm %02X, became 'not operational'\n",
+			      cdev->private->devno, sch->schid.ssid,
+			      sch->schid.sch_no, cdev->private->imask);
+		return -EACCES;
+	}
+	return 0;
+}
+
 static void
 __ccw_device_verify_start(struct ccw_device *cdev)
 {
@@ -296,9 +367,12 @@ __ccw_device_verify_start(struct ccw_device *cdev)
 			if ((sch->vpm & imask) != (sch->lpm & imask))
 				break;
 		cdev->private->imask = imask;
-		func = (sch->vpm & imask) ?
-			SPID_FUNC_RESIGN : SPID_FUNC_ESTABLISH;
-		ret = __ccw_device_do_pgid(cdev, func);
+		if (cdev->private->options.pgroup) {
+			func = (sch->vpm & imask) ?
+				SPID_FUNC_RESIGN : SPID_FUNC_ESTABLISH;
+			ret = __ccw_device_do_pgid(cdev, func);
+		} else
+			ret = __ccw_device_do_nop(cdev);
 		if (ret == 0 || ret == -EBUSY)
 			return;
 		cdev->private->iretry = 5;
@@ -327,7 +401,10 @@ ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
 	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
 		return;
 	sch = to_subchannel(cdev->dev.parent);
-	ret = __ccw_device_check_pgid(cdev);
+	if (cdev->private->options.pgroup)
+		ret = __ccw_device_check_pgid(cdev);
+	else
+		ret = __ccw_device_check_nop(cdev);
 	memset(&cdev->private->irb, 0, sizeof(struct irb));
 	switch (ret) {
 	/* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
@@ -345,11 +422,10 @@ ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
 		 * One of those strange devices which claim to be able
 		 * to do multipathing but not for Set Path Group ID.
 		 */
-		if (cdev->private->flags.pgid_single) {
-			ccw_device_verify_done(cdev, -EOPNOTSUPP);
-			break;
-		}
-		cdev->private->flags.pgid_single = 1;
+		if (cdev->private->flags.pgid_single)
+			cdev->private->options.pgroup = 0;
+		else
+			cdev->private->flags.pgid_single = 1;
 		/* fall through. */
 	case -EAGAIN:		/* Try again. */
 		__ccw_device_verify_start(cdev);
diff --git a/drivers/s390/cio/device_status.c b/drivers/s390/cio/device_status.c
index 14bef2c179bf..caf148d5caad 100644
--- a/drivers/s390/cio/device_status.c
+++ b/drivers/s390/cio/device_status.c
@@ -67,8 +67,7 @@ ccw_device_path_notoper(struct ccw_device *cdev)
 		      sch->schib.pmcw.pnom);
 
 	sch->lpm &= ~sch->schib.pmcw.pnom;
-	if (cdev->private->options.pgroup)
-		cdev->private->flags.doverify = 1;
+	cdev->private->flags.doverify = 1;
 }
 
 /*
@@ -180,7 +179,7 @@ ccw_device_accumulate_esw(struct ccw_device *cdev, struct irb *irb)
 	cdev_irb->esw.esw0.erw.auth = irb->esw.esw0.erw.auth;
 	/* Copy path verification required flag. */
 	cdev_irb->esw.esw0.erw.pvrf = irb->esw.esw0.erw.pvrf;
-	if (irb->esw.esw0.erw.pvrf && cdev->private->options.pgroup)
+	if (irb->esw.esw0.erw.pvrf)
 		cdev->private->flags.doverify = 1;
 	/* Copy concurrent sense bit. */
 	cdev_irb->esw.esw0.erw.cons = irb->esw.esw0.erw.cons;
@@ -354,7 +353,7 @@ ccw_device_accumulate_basic_sense(struct ccw_device *cdev, struct irb *irb)
 	}
 	/* Check if path verification is required. */
 	if (ccw_device_accumulate_esw_valid(irb) &&
-	    irb->esw.esw0.erw.pvrf && cdev->private->options.pgroup) 
+	    irb->esw.esw0.erw.pvrf)
 		cdev->private->flags.doverify = 1;
 }
 
diff --git a/drivers/s390/s390mach.c b/drivers/s390/s390mach.c
index ffb3677e354f..5399c5d99b81 100644
--- a/drivers/s390/s390mach.c
+++ b/drivers/s390/s390mach.c
@@ -111,6 +111,16 @@ s390_collect_crw_info(void *param)
 			break;
 		case CRW_RSC_CPATH:
 			pr_debug("source is channel path %02X\n", crw[0].rsid);
+			/*
+			 * Check for solicited machine checks. These are
+			 * created by reset channel path and need not be
+			 * reported to the common I/O layer.
+			 */
+			if (crw[chain].slct) {
+				DBG(KERN_INFO"solicited machine check for "
+				    "channel path %02X\n", crw[0].rsid);
+				break;
+			}
 			switch (crw[0].erc) {
 			case CRW_ERC_IPARM: /* Path has come. */
 				ret = chp_process_crw(crw[0].rsid, 1);
diff --git a/include/asm-s390/cio.h b/include/asm-s390/cio.h
index 2b1619306351..28fdd6e2b8ba 100644
--- a/include/asm-s390/cio.h
+++ b/include/asm-s390/cio.h
@@ -276,6 +276,8 @@ extern void wait_cons_dev(void);
 
 extern void clear_all_subchannels(void);
 
+extern void cio_reset_channel_paths(void);
+
 extern void css_schedule_reprobe(void);
 
 #endif